Figure 4
Impaired glucose transport and alterations in insulin signaling. (a) Insulin-stimulated glucose transport was determined using nonmetabolizable [3H]2-deoxy-d-glucose. The results are expressed as a percentage of glucose transport measured in the absence of insulin separately for ASC-As and FAP-As. ASC-As values are represented with gray bars (n=4; ASC biopsies 1, 2, 3, and 4) and FAP-As values with black bars (n=8; FAP biopsies 3, 4, 5, 6, 7, 13, 14, and 15). (b) mRNA relative expression of Glut4 and IR measured by quantitative RT-PCR. n=3 for ASC-As (ASC biopsies 1, 3, and 4) and FAP-As (FAP biopsies 4, 6, and 7). The results are mean±S.E. of the mean for three independent measurements. (c) Phosphorylations were compared in adipocytes without insulin treatment and with 100 nM insulin stimulation, for 20 min. Cell lysates were subjected to immunoblotting with specific antibodies. Representative blots are shown. (d) Immunoblot signals were quantified and normalized with tubulin signals. Phosphorylated-form contents are expressed as fold change induced by insulin relative to the absence of insulin treatment. The phosphorylations concern IR tyrosines, IRS-1 tyrosines, Akt-Thr308, 42 MAPK-Thr202, and 44 MAPK-Tyr204. ASC-As values (n=3; ASC biopsies 1, 2, and 4) are represented with gray bars and FAP-As values in black bars (n=6; FAP biopsies 1, 2, 8, 9, 10, and 12; except for 42 and 44 MAPK where n=4; FAP biopsies 1, 2, 8, and 9). Data are expressed as mean±S.E. of the mean. (e and f) Relative mRNA contents of PTP1B and SHP2 were measured by quantitative RT-PCR and expressed as a percentage of values found in ASC-As. For ASC-As, n=5 (ASC biopsies 1, 2, 3, 4, and 5); for FAP-As, n=7 (FAP biopsies 2, 4, 6, 8, 9, 10, and 12). The results are mean±S.E. of the mean for three independent measurements. *P<0.05 and **P<0.01
